Contamination of groundwater with arsenic and 32 other toxic compounds in Vietnam's Red River Delta poses a health hazard for 7 million people in this area, according to findings of researchers from Switzerland and Vietnam (Winkel LHE et al. Proc Natl Acad Sci U S A. 10.1073/pnas.1011915108 [published online ahead of print, January 18, 2011]).